1. Field
A scroll compressor is disclosed herein.
2. Background
In general, a refrigerant compressor may be applied to a vapor compression type refrigerating cycle (hereinafter, referred to as a “refrigerating cycle”), such as a refrigerator or an air conditioner. Refrigerant compressors may include a uniform speed type compressor, which operates at a uniform speed, and an inverter type compressor, whose rotational speed is controlled.
A refrigerant compressor, in which a drive motor, which is generally an electric motor, and a compression device driven by the drive motor are all installed within an inner space of a hermetic casing, may be a hermetic compressor. A refrigerant compressor, in which a drive motor is separately installed outside of a casing, may be an open type compressor. Most household or commercial refrigerating apparatuses employ the hermetic compressor.
The refrigerant compressors may be classified into a reciprocating type, a scroll type, and a rotary type according to a method of compressing a refrigerant. The scroll compressor is a compressor in which a fixed scroll is fixed in an inner space of a hermetic container, and an orbiting scroll orbits while being engaged with the fixed scroll such that a pair of compression chambers, which continuously move between a fixed wrap of the fixed scroll and an orbiting wrap of the orbiting scroll, are formed.
The scroll type compressor is widely used to compress a refrigerant in an air-conditioning apparatus, by virtue of advantages of obtaining a relatively higher compression ratio than other types of compressors and obtaining a stable torque resulting from a smooth connection of suction, compression, and discharge strokes of a refrigerant.
However, as the related art scroll compressor, as illustrated in FIG. 1, has a fixed wrap (a shape of this wrap is the same as that of the orbiting wrap, and thus, the orbiting wrap will be representatively described) of the fixed scroll, and an orbiting wrap 1a of an orbiting scroll formed in an involute shape, the wraps are eccentrically formed. Accordingly, an area (A) which cannot be used as a compression chamber is formed at an outer portion of each scroll 1 (fixed scroll not illustrated). As a result, a compression capacity is lowered for a same diameter, or an outer diameter of the compressor is increased for the same capacity.
Also, when the fixed wrap and the orbiting wrap 1a of the related art are formed in the shape of the involute curve, a thickness (t) of each wrap is typically uniform and a capacity variation ratio constant. Therefore, in order to obtain a high volume ratio (namely, a high compression ratio) in the scroll compressor, a number of turns of the wrap or a height of the wrap has to be increased. However, if the number of turns of the wrap is increased, the compressor is increased in size, and if the height of the wrap is increased, intensity of the wrap is lowered. This results in lower reliability of the compressor.